1. Field of the Invention
The present invention relates to a method and apparatus for tracking an object, and a method and apparatus for calculating object pose information, and more particularly, to a method and apparatus for automatically tracking an object in real time and estimating an object pose from an input video image, and a method and apparatus for calculating object pose information.
2. Description of the Related Art
A technique of detecting a predetermined object from a video image and tracking the predetermined object has been developed in the fields of security and face recognition. In the case of a security system, in order to automatically detect a person who enters a detection zone, it is necessary to detect an object which enters the detection zone and track the motion of the object. A difference method is used as a typical method of tracking an object.
In the difference method, the object is tracked by using the difference between an input image obtained by an image acquisition device and a prepared reference image.
In US patent publication No. 2003/0031344, a method is disclosed in which a user directly assigns locations of at least one tracking node, reinitializes the tracking nodes, and automatically tracks off-line face features based on the renormalized tracking nodes. However, in the aforementioned patent, when the object is changed, the user has to directly renormalize the tracking nodes so as to track a new object.
In US patent publication No. 2004/0240708, a method of using a repeated sum of squares difference (SSD) and a method in which a pose is estimated by recognizing a shape change of a 2-dimensional (2D) triangle are disclosed. However, in this case, since a face image is simplified as a 2D triangle, the accuracy of estimating the poses decreases.
In addition, existing methods of tracking an object using an optical flow are weak in terms of partial occlusion. It takes much processing time to track an object by using the existing methods. Accordingly, it is difficult to apply the existing methods to a system for tracking an object in real time.